Temporomandibular Joint Disorder

<< What Is Temporomandibular Joint Disorder >>

• Temporomandibular joint disorder is often also called "TMJ disorder," and because it usually includes pain disorders such as headaches, it is also referred to as "temporomandibular disorder" or "craniomandibular disorder." Traditionally, temporomandibular joint disorder was thought of as a single syndrome, but recent research views it as a complex of related masticatory system disorders that share many common features. The most common symptom of temporomandibular joint disorder is pain, which usually appears in the masticatory muscles, the area of the TMJ, or both, and is characterized by worsening with chewing or other jaw functions.

• Typical patients with temporomandibular joint disorder complain of pain in the jaw, ears, head, or face, and may experience limited jaw movement, an asymmetrical jaw shape, or various noises coming from the TMJ. In addition, poor oral habits such as bruxism, painless masticatory muscle hypertrophy, and abnormal wear may also be seen.

• In other words, temporomandibular joint disorder mainly consists of disorders of the TMJ itself and head and neck muscle disorders, including tension-type headaches. Meanwhile, pain or dysfunction of the masticatory system caused by non-musculoskeletal conditions such as otolaryngological diseases, neurological diseases, vascular diseases, neoplasms, and infectious diseases in the oral and facial region is not considered primary temporomandibular joint disorder. However, temporomandibular joint disorder can often coexist with other craniofacial pain disorders.

• According to epidemiological studies of temporomandibular joint disorder, about 75% of Westerners have at least one sign of dysfunction (joint sounds, tenderness, etc.), and about 33% have at least one symptom. A study of Korean college students found that 53% had one or more self-reported symptoms, and 32% had facial pain and headaches.

<< Causes of Temporomandibular Joint Disorder >>

1. Biological factors - Biological contributing factors directly affect pathophysiology and sustain pain. According to the data, skeletal deformities, genetic predisposition, past injuries, and other systemic/dental problems are associated with various conditions that cause orofacial pain. A forward head position and other posture problems may act as causative factors for muscle or joint dysfunction, and may also appear as a result of such disorders.

2. Behavioral factors - Behavioral contributing factors refer to anything involving regular behaviors, habits, and actions that affect pain syndromes. These usually have a direct effect on the persistence of pain syndromes, and these factors can often be artificially controlled or modified through behavioral treatment plans. The most common of these behaviors are oral parafunctional habits, which include bruxism, deviated swallowing, nail biting, lip biting, biting objects, chewing gum, habits of protruding or retracting the jaw, habits of protruding the tongue, and habits of opening the mouth using the facial muscles and suprahyoid muscles.

Other lifestyle habits, such as irregular eating, nutritionally deficient meals, and excessive caffeine intake through drinks or medication, are also associated with chronic craniofacial pain.

3. Environmental factors - These refer to stimuli in a person's physical environment that cannot be directly controlled but contribute to pain problems. They affect a person's perception of and response to pain and illness, which can make treatment very complex. Chronic exposure to toxic substances such as lead, mercury, and arsenic can directly cause pain problems like neuralgia, and stimuli such as chronic vibration, noise, inadequate lighting, and excessive use of video terminals can also be problematic.

4. Social factors - This refers to the person's prior or subsequent social environment that affects pain perception and learned pain responses. The relationship between stressful everyday events and physical illness is unclear, but the literature has emphasized that there is an indirect interactive relationship between the two and that a multifaceted approach is needed to explain its effects.

5. Emotional factors - Emotional contributing factors include long-term negative emotions that make treatment difficult or indirectly sustain other contributing factors. They are thought to affect pain indirectly. Emotions such as anxiety, anger, and depression can worsen the doctor-patient relationship, increase muscle tension, hinder sufficient understanding of the clinical problem, and reduce the desire or motivation for change, thereby affecting patient compliance. Encouraging recognition and expression of emotions and listening carefully can often help relieve mild or temporary emotional disorders. If emotional problems are the primary issue, it is difficult to treat both problems at the same time, so treatment for the emotional problem should come before other treatments.

6. Cognitive factors - Cognitive contributing factors are indirect factors and often accompany emotional factors. They include dominant thought processes or attitudes that work unproductively toward improving the condition. Because patients have long heard different opinions about the causes of their symptoms and treatment methods, a lack of understanding and confusion about the problem are common among chronic pain patients. These factors can make treatment difficult by reducing motivation, causing anger, and leading to poor compliance with the doctor's instructions, so they should be considered in the doctor-patient relationship, treatment plan, and prognosis.

Source - Korea Disease Control and Prevention Agency National Health Information Portal